you are given 2.674 g of a mixture of KClO3 and KCl. when heated the KClO3 decomposes to KCl and O2.
2KCl03 (s) —> 2 KCl (s) +3 O2 (g)
and 758 mL of O2 is collected over water at 21 degrees celsius . the total pressure of the gases in the collection flask is 725 mm Hg. what is the weight percentage of KCl03 in the sample?
the formula weight of KClO3 is 122.55 g/mol
the vapor pressure of water at 21 degrees is 18.7 mm Hg.
Use PV=nRT to solve to get moles of product then relate back to reaction.
Chris G | Nov 23, 2009